There is a need to obtain and provide measurements of subsea objects to determine strain of parts or corrosion, but not limited to these circumstances. Traditionally, subsea operators have attempted to take physical, lineal measurements of physical features subsea by using laser line scans, photogrammetry or simple, non-adjustable, “go/no-go” gauges. Often, they have not had the accuracy necessary to measure quantities such as strain due to load (stress) or thickness change due to corrosion. These methods also were difficult to use, had to be adjusted on the surface, or required “post-processing” of the information to yield a measurement. What has been needed for some time is a way to take an accurate linear measurement subsea, in realtime, using a tool that is designed for integration with an ROV control system.